1.2.2 Exhaust Valves
DETROIT DIESEL 53
When a new valve seat insert is installed or an old insert
refaced, the work must be done with a grinding wheel
Fig. 9.- Refacing Exhaust Valve
(Fig. 10).
Recondition Exhaust Valve and Valve Insert
The eccentric grinding method for reconditioning valve
seat inserts is recommended. This method produces a
An exhaust valve which is to be reused may be refaced,
finer, more accurate finish since only one point of the
if necessary (Fig. 9). To provide sufficient valve
grinding wheel is in contact with the valve seat at any
strength and spring tension, the edge of the valve at the
time. A micrometer feed permits feeding the grinding
valve head must not be less than 1/32" in thickness and
wheel into the work .001" at a time.
must still be within the specifications shown in Fig. 11
after refacing.
Before either a new or used valve is installed, examine
the valve seat in the cylinder head for proper valve
seating. The angle of the valve seat insert must be
exactly the same as the angle of the valve face to
provide proper seating of the valve. The proper angle
for the seating face of both the valve and valve seat
insert is 30.
To grind the valve seat inserts use the following tools:
1. Grinder J 8165-1
2. Dial Gage J 8165-2
3. Pilot J 7792-1
4. Grinding Wheel (15) J 7792-2
5. Grinding Wheel (30) J 7792-3
6. Grinding Wheel (60) J 7792-4
Grind the valve seat inserts as follows:
Fig. 10.- Grinding Valve Seat Insert
1. First apply the 30 grinding wheel on the valve seat
insert.
1972 General Motors Corp.
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